1. Technical Field of the Invention
The present invention relates to a shielding device with a shielding element, which can be used for the thermal and acoustic shielding of components in a combustion engine. The present invention particularly relates to a mounting of the shielding device, in which a thermal, acoustic and vibration transmission from hot, loud and vibrating components in the engine compartment or underbody area to a vehicle body is isolated.
2. Related Art
Shielding elements have wide-ranging uses. Special applications of shielding devices are found particularly in the vehicle industry, where they are used as heat shields to protect passengers or components, for example, from heat and noise generated in the engine. Such components are primarily parts of the exhaust system, such as catalytic converters, exhaust manifolds, turbochargers and the like. The shielding elements are designed to shield the vehicle interior from high temperatures and noise resulting from vibrations. In order to satisfy the increasingly rigorous regulations on the outside noise level of vehicles, the shielding elements should absorb a high degree of noise.
For these sorts of applications, the shielding elements must be sufficiently firm and rigid to retain their shape when there are high loads and, in addition, to protect passengers from a significant proportion of the heat and vibration generated.
The use of a single metal sheet made from aluminium or an alloy, for example, is often insufficient, because although such a metal sheet is able to reduce infrared radiation and convection, its acoustic damping properties, for example, are too low.
In addition, the shielding elements mentioned in the state of the art exhibit the unfavourable property of transmitting the thermal radiation, acoustic waves and vibrations absorbed by the shielding element for example to the mounting points of the vehicle body and therefore ultimately to the vehicle body, so that passengers and heat-sensitive parts of the vehicle no longer have optimum protection.
This sort of shielding element is disclosed in EP 0 917 507 B1, for example. This discloses a method of producing a thermally insulating composite panel. However, the problem of limiting the thermal, acoustic and vibration transmission to the components surrounding the composite panel is not dealt with here.
DE 43 29 411 C2 also deals with a thermal, acoustic and vibration insulating material and a method of producing it. In this case, a thermal, acoustic and vibration damping material is disclosed, which is made up of several profiled sheets of non-ferrous metal, particularly aluminium, laid on top of one another.
The material may be used as industrial insulation and also as a heat protection shield in vehicle and rolling stock construction. The problem of adequate containment of the thermal, acoustic and vibration transmission to the components surrounding the composite panel is not solved by this either. Furthermore, an insulating effect is only achieved by the shielding elements themselves, while the mounting points of the shielding element and the component being shielded are exposed to high thermal and mechanical loads.